对于这个问题的迟到者，http://www.sqlperformance.com/2012/07/t-sql-queries/split-strings 上的文章对各种选项的性能进行了出色的分析。考虑的一些选项包括（从网站复制以供参考）：
CLR
.Net 代码http://dataeducation.com/sqlclr-string-splitting-part-2-even-faster-even-more-scalable/。
CREATE ASSEMBLY CLRUtilities FROM 'c:\DLLs\CLRUtilities.dll'
WITH PERMISSION_SET = SAFE;
GO
CREATE FUNCTION dbo.SplitStrings_CLR
(
@List NVARCHAR(MAX),
@Delimiter NVARCHAR(255)
)
RETURNS TABLE ( Item NVARCHAR(4000) )
EXTERNAL NAME CLRUtilities.UserDefinedFunctions.SplitString_Multi;
GO
XML
CREATE FUNCTION dbo.SplitStrings_XML
(
@List NVARCHAR(MAX),
@Delimiter NVARCHAR(255)
)
RETURNS TABLE
WITH SCHEMABINDING
AS
RETURN
(
SELECT Item = y.i.value('(./text())[1]', 'nvarchar(4000)')
FROM
(
SELECT x = CONVERT(XML, '<i>'
+ REPLACE(@List, @Delimiter, '</i><i>')
+ '</i>').query('.')
) AS a CROSS APPLY x.nodes('i') AS y(i)
);
GO
CTE
CREATE FUNCTION dbo.SplitStrings_CTE
(
@List NVARCHAR(MAX),
@Delimiter NVARCHAR(255)
)
RETURNS @Items TABLE (Item NVARCHAR(4000))
WITH SCHEMABINDING
AS
BEGIN
DECLARE @ll INT = LEN(@List) + 1, @ld INT = LEN(@Delimiter);
WITH a AS
(
SELECT
[start] = 1,
[end] = COALESCE(NULLIF(CHARINDEX(@Delimiter,
@List, @ld), 0), @ll),
[value] = SUBSTRING(@List, 1,
COALESCE(NULLIF(CHARINDEX(@Delimiter,
@List, @ld), 0), @ll) - 1)
UNION ALL
SELECT
[start] = CONVERT(INT, [end]) + @ld,
[end] = COALESCE(NULLIF(CHARINDEX(@Delimiter,
@List, [end] + @ld), 0), @ll),
[value] = SUBSTRING(@List, [end] + @ld,
COALESCE(NULLIF(CHARINDEX(@Delimiter,
@List, [end] + @ld), 0), @ll)-[end]-@ld)
FROM a
WHERE [end] < @ll
)
INSERT @Items SELECT [value]
FROM a
WHERE LEN([value]) > 0
OPTION (MAXRECURSION 0);
RETURN;
END
GO
功能
CREATE FUNCTION dbo.SplitStrings_Moden
(
@List NVARCHAR(MAX),
@Delimiter NVARCHAR(255)
)
RETURNS TABLE
WITH SCHEMABINDING AS
RETURN
WITH E1(N) AS ( SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1
UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1
UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1),
E2(N) AS (SELECT 1 FROM E1 a, E1 b),
E4(N) AS (SELECT 1 FROM E2 a, E2 b),
E42(N) AS (SELECT 1 FROM E4 a, E2 b),
cteTally(N) AS (SELECT 0 UNION ALL SELECT TOP (DATALENGTH(ISNULL(@List,1)))
ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E42),
cteStart(N1) AS (SELECT t.N+1 FROM cteTally t
WHERE (SUBSTRING(@List,t.N,1) = @Delimiter OR t.N = 0))
SELECT Item = SUBSTRING(@List, s.N1, ISNULL(NULLIF(CHARINDEX(@Delimiter,@List,s.N1),0)-s.N1,8000))
FROM cteStart s;
事实证明，最好的性能来自使用 CLR 函数，而 XML 解决方案也做得很好。几乎在所有情况下，使用数字表（上面没有重复该方法）都会导致最差的性能。